Carbonators and carbonation systems are old and commonly used. While such systems are particularly used in soft drink dispensers, it is also known that many individuals simply enjoy drinking carbonated water or soda whether flavored or not. Such soda is commonly generated by introducing a pressure head of carbon dioxide gas onto a reservoir of water in such a manner as to entrain the carbon dioxide gas in the water. It is known in the art that a pressure head of carbon dioxide gas on the order of 75 psi is sufficient to generate soda from water when the water is at a temperature of approximately 70.degree.. At such a temperature and pressure, the water and carbon dioxide gas will stabilize or saturate at a suitable level to obtain a desired taste. However, the level of saturation is indeed a function of both temperature and pressure.
Prior art carbonators have typically required the implementation of a motor to drive water under pressure into a tank having a pressure head on the order of 100 psi. The motor must be of sufficient size to overcome the tank pressure of the carbonator and, consequently, results in the generation of unwanted heat. The motor heat is transferred to the water which is to be carbonated, reducing the effectiveness of the carbonation process.
It is further known that carbonation tanks require the utilization of a float switch which is operative through relays and the like to actuate the motor upon demand to supply additional water to the carbonation tank. Such float switches are troublesome and, indeed, comprise a commonly-replaced element in the prior art carbonation systems.
The motor referenced above is employed to operate a pump for actually driving the water. The pump is typically of brass or stainless steel to operate in the food industry and must be of sufficient design criteria as to operate under high pressure. It has previously been known that such pumps often "burn out" when they are starved of water, for example, when the demands of the water supply to the operating environment reduce the amount of water available to the carbonation system to an insufficient level. Indeed, the prior art teaches the utilization of expensive and unreliable methods of determining when the water supply is inadequate such that the motor and pump can be turned off. Such prior methods have included both thermal and pressure sensors.
Yet further, the prior art has taught the necessity of precooling tubing to be maintained between the pump and the tank such that the water introduced to the tank can be precooled in order that the carbonation process may be enhanced.
The foregoing structure and techniques of the prior art have been extremely expensive both in initial cost and in operation. The pump, motor, float switch and controlling circuitry are both expensive in implementation and costly in repair. Accordingly, there is a need in the art for a carbonation system which can operate without electrical motors, high pressure pumps, high power control circuitry, float switches and the requisite maze of precooling tubing.